The earlier post was deleted prob because it specifically named a "doctor" who is not a real one anyway

In the earlier post, some ill-informed person (either this or he's someone who is offering this service and subtly promoting this con/sham "treatment") said "The practice of colonic hydrotherapy is very old, commonly used for constipation and arthritis."

LOL! It is very old but it does not mean it is effective.

I doubt you will find any proper evidence that it is effective for the treatment of anything.

The lesson, folks, is not to see anyone with a "Dr" in front of his name, if he is not what most persons would consider to be a real one, i.e. those listed at:
https://www.mchk.org.hk/english/list_register/doctor_list.php

Lesson of the day: Don't get a rectal ulcer/bleeding! Don't do colon "hydrotherapy"! Don't see "fake Drs"!